One of the most exhausting things about politics is a mindset that says "scandal for thee, but not for me."

Consider the perennial (alleged) scandal of presidential golf. When George W. Bush was commander in chief, he played a lot of golf, and his critics were outraged -- or at least pretended to be.

Whether it was the political pressure or his own conscience, President Bush ultimately decided to stop golfing. "I don't want some mom whose son may have recently died to see the commander in chief playing golf," Bush told Politico in 2008. "I feel I owe it to the families to be in solidarity as best as I can with them."

Now it's President Obama who plays a lot of golf. According to the website Obamagolfcounter.com (yes, you read that right), he'd hit the links on 270 days of his presidency as of Jan. 1. In March, the number reached 281. That's roughly 10 percent of his presidency.

But the left-wing crowd that denounced Bush for golfing has fallen silent, while the right-wing crowd that didn't care a whit about how Bush let loose is incensed by Obama's leisure activity.

One can play the same game with presidential vacations.

Whenever Obama chooses not to let a terrorist attack or other emergency cut short his time off, his supporters justify his absence by insisting that the president shouldn't be held "hostage" to the news cycle, or that he shouldn't get in the way of first responders. That's what they said last week when Obama stayed put in Martha's Vineyard instead of surveying flood damage in Louisiana.

These are good excuses, but ones that never seemed to work for his predecessor.

"We can talk about levees that couldn't hold, about a FEMA that seems not just incompetent but paralyzed and powerless. About a president who only saw the people from the window of an airplane instead of down here on the ground," Obama preached in New Orleans in 2005.

In 2007, after the Bush administration had spent more than $100 billion on Katrina recovery efforts, Hillary Clinton was still saying the victims were "invisible" to Bush.

Perhaps Donald Trump had these criticisms in mind when, in a shrewd political move last week, he flew to Louisiana, shaming Obama into announcing he would also survey the damage in person.

Of course, politics is about more than simply making the best decisions on the merits. "Optics," as the political consultants say, matter. Asked why he hadn't been to Louisiana earlier, Trump explained helpfully, "I had nothing to gain before."

But the fact remains that the standards of politics often move like a seesaw, with the weight of one side's hypocrisy elevating the other. And that's OK for partisans. They are supposed to seek advantage over their opponents.

I'm much less forgiving of the media. Hurricane Katrina was undoubtedly a huge story, and investigating the federal response to it was squarely in the fourth estate's wheelhouse. But there's simply no denying that the news media used that disaster as a partisan cudgel against a Republican president it detested.

Worse, the media congratulated itself endlessly for its Katrina coverage despite the fact that it collectively did a terrible job. Reports of roving rape gangs were broadcast uncritically. While the media employed heroic skepticism about Bush's assurances, the New Orleans police chief's claim of "little babies getting raped" in the Superdome sailed on through. One activist at the Huffington Post reported that four days after the storm, black people had resorted to eating the flesh of the dead.

Eleven years later, Louisiana is suffering through another flood disaster. Where's the outraged swarm coverage of Obama's (non-)response?

Journalism students are famously taught, "If your mother says she loves you, check it out." But they also seem to have been instructed that if a president you hate is on the ropes, let it fly; if a president you love is in the same spot, fall silent.